This invention relates generally to clamps and specifically to a powered, force multiplying apparatus.
In the clamping and sheet metal joining industries, it is commonly known to provide a clamping mechanism for temporarily or permanently securing sheets of material. Typically, these traditional clamps are limited to a pivoting movement, a linear movement, or a linear then pivoting movement, when a clamping arm is moved between an open/retracted position to a closed/material engaging position.
Examples of traditional clamping arm movement in the rotational manner is disclosed within the following U.S. patents: U.S. Pat. No. 5,171,001 entitled "Sealed Power Clamp"; U.S. Pat. No. 5,165,670 entitled "Retracting Power Clamp"; and U.S. Pat. No. 5,118,088 entitled "Power Clamp"; all of which were invented by the inventor of the present invention. A variety of linear motion clamping arms are disclosed within the following U.S. patents: U.S. Pat. No. 4,574,473 entitled "Self-Attaching Fastener and Apparatus for Securing Same to Sheet Material"; and U.S. Pat. No. 3,730,044 entitled "Fluid Operated Apparatus"; both of which were invented by the inventor of the present invention and are incorporated by reference herewithin. Other clamping devices have been employed such as those disclosed within the following U.S. patents: U.S. Pat. No. 5,193,789 entitled "Automatic Clamping Apparatus" which issued to Tucker; U.S. Pat. No. 4,723,767 entitled "Rotary Powered Linear Actuated Clamp" which issued to McPherson et al.; U.S. Pat. No. 3,599,957 entitled "Cam Wedge Power Swing Away With Guided Arm" which issued to Blaft; and U.S. Pat. No. 3,482,830 entitled "Clamp" which issued to Sendoykas; all of which are incorporated by reference herewithin. While many of these constructions have proven satisfactory, it would be desirable to achieve greater clamping force with less driving force.
In accordance with the present invention, the preferred embodiment of a force multiplying apparatus employs a pivoting clamping arm motion and then a subsequent linear clamping arm motion. In another aspect of the present invention, a slotted swing arm and a slotted drive link are pivotably and slidably mounted to a relatively fixed body. In yet another aspect of the present invention, a punch is mounted upon a distal section of the clamping arm for acting in conjunction with a die thereby clinching or otherwise joining sheets of material disposed therebetween.
The apparatus of the present invention is advantageous over traditional constructions since the present invention provides the ability to significantly multiply or increase the clamping forces without requiring a corresponding increase in the actuator or driving forces. The present invention force multiplying apparatus additionally achieves a more accurate and secure joint between material sheets due to the final linear motion of the clamping arm. As another advantage, the present invention is extremely durable and reliable by employing more robust and less delicate component parts as compared to many conventional constructions. Additional advantages and features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.